Predischarge two-dimensional echocardiographic evaluation of left ventricular thrombosis after acute myocardial infarction in the GISSI-3 study

Prophylactic Anticoagulation to Prevent Left Ventricular Thrombus Following Acute Myocardial Infarction: A Systematic Review and Meta-Analysis

Clinical practice guidelines from the American Heart Association recommend consideration of prophylactic anticoagulation to prevent left ventricular thrombus (LVT) formation in patients with anterior ST-elevation myocardial infarction. These guidelines were given a low certainty of evidence (class IIb, level C), relying primarily on case studies and expert consensus to inform practice. Our objective was to compare the safety and efficacy of prophylactic anticoagulation, in addition to dual antiplatelet therapy, in the current era of timely primary percutaneous coronary intervention. Electronic databases, including EMBASE, MEDLINE, and Cochrane Library, were systematically searched from January 2012 through June 2022. A total of 7,378 publications were screened, and 5 publications were eventually included in this review: 1 randomized control trial and 4 retrospective studies involving 1,461 patients. Data were pooled using a fixed-effects model and reported as odds ratios (ORs) with 95% confidence intervals (CIs). The primary outcome of interest was the rate of LVT formation, and the secondary outcomes were the rate of major bleeding and systemic embolism. Pooled analysis showed a significantly lower rate of LVT formation (OR 0.28, 95% CI 0.11 to 0.73, p <0.01) and significantly higher rates of bleeding (OR 2.85, 95% CI 1.13 to 7.24, p = 0.03) in the triple therapy group compared with dual antiplatelet therapy. No significant difference was observed in the rate of systemic embolism between the groups (OR 0.37, 95% CI 0.12 to 1.13, p = 0.08). In this meta-analysis, there is no conclusive evidence to either support or oppose the use of triple therapy for LVT prevention in patients with anterior ST-elevation myocardial infarction treated with primary percutaneous coronary intervention. Appropriately powered randomized controlled trials are warranted to further evaluate the benefits of LVT prevention against the risks of major bleeding in this population.

Safety of dobutamine or adenosine stress cardiac magnetic resonance imaging in patients with left ventricular thrombus

BACKGROUND

Left ventricular (LV) thrombus formation is a common but potentially serious complication, typically occurring after myocardial infarction. Due to perceived high thromboembolic risk and lack of safety data, stress cardiac magnetic resonance (CMR) imaging especially with dobutamine is usually avoided despite its high diagnostic yield. This study aimed to investigate the characteristics, safety and outcome of patients with LV thrombus undergoing dobutamine or vasodilator stress CMR.

METHODS

Patients undergoing stress CMR with concomitant LV thrombus were retrospectively included. Risk factors, comorbidities, and previous embolic events were recorded. Periprocedural safety was assessed for up to 48 h following the examination. Major adverse cardiac events (MACE) 12 months before the diagnosis were compared to 12 months after the exam and between patients and a matched control group. Additionally, patients were followed up for all-cause mortality.

RESULTS

95 patients (78 male, 65 ± 10.7 years) were included. Among them, 43 patients underwent dobutamine (36 high-dose, 7 low-dose) and 52 vasodilator stress CMR. Periprocedural safety was excellent with no adverse events. During a period of 24 months, 27 MACE (14.7%) occurred in patients and controls with no statistical difference between groups. During a median follow-up of 33.7 months (IQR 37.6 months), 6 deaths (6.3%) occurred. Type of stress agent, thrombus mobility, or protrusion were not correlated to embolic events or death.

CONCLUSION

The addition of a stress test to a CMR exam is safe and does increase the generally high cardioembolic event rate in LV thrombus patients. Therefore, it is useful to support reperfusion decision-making.

Analysis of Echocardiographic Findings of Patients with Acute Ischemic Stroke Admitted to a Tertiary Care Hospital in Mogadishu, Somalia

Background and Aims

The etiological investigation of the potential cardiac source of acute ischemic stroke is important for the secondary prevention of recurrent and future embolization. Transthoracic echocardiography is one of the most useful investigations for the assessment of the potential cardiac etiology of ischemic stroke. Our aim is to evaluate echocardiographic findings in patients with acute ischemic stroke admitted to a tertiary care hospital in Mogadishu, Somalia.

Methods

This was a retrospective observational study conducted in the neurology department of a tertiary care hospital in Mogadishu, Somalia. We enrolled 315 patients with acute ischemic stroke admitted to the hospital who had undergone transthoracic echocardiography between March 2019 and March 2022. We analyzed transthoracic echocardiography findings, ischemic stroke subtypes, and their associated comorbidities. We also compared the demographic data, comorbidity, and survival status of patients with abnormal echo findings to those with normal echo findings.

Findings

The mean age of patients was 62±12 years. Co-morbidities were present in about 251 (80%) of the subjects, hypertension was the most common comorbidity 99 (31.4%), followed by diabetes 72 (23%), and hyperlipidemia 37 (11.7%). Overall cardiac pathology in this study was 170 (54%). Forty-seven (15%) of the patients had low ejection fraction on transthoracic echocardiography. Male patients had slightly less left ventricular systolic dysfunction than female patients. 100 (32%) had left ventricular diastolic dysfunction (LVDD), while 113 (36%) had left ventricular hypertrophy (LVH). Patients with hypertension and diabetes had more echo abnormalities compared to others (P-values of 0.047 and 0.024, respectively). More abnormal echo findings were seen in patients who died during hospitalization than in those who survived (P = 0.008). Severe left ventricular systolic dysfunction was associated with higher mortality (P < 0.001).

Conclusion

Most patients with stroke in this study had abnormal echocardiograms; however, only a few had cardioembolic strokes. Abnormalities in echocardiography were more common in patients who died during hospitalization than in those who survived.

What's the optimal duration of anticoagulation in patients with left ventricular thrombus?

INTRODUCTION

Left ventricular thrombus (LVT) occurs in acute myocardial infarction and in ischemic and non-ischemic cardiomyopathies. LVT may result in embolic stroke. Currently, the duration of anticoagulation for LVT is unclear. This is an important clinical question as prolonged anticoagulation is associated with increased bleeding risks, while premature discontinuation may result in embolic complications.

AREAS COVERED

There are no randomized trial data regarding anticoagulation duration for LVT. Guidelines and expert consensus recommend anticoagulation for 3-6 months with cessation of anticoagulation if interval imaging demonstrates thrombus resolution. Cardiac magnetic resonance imaging (CMR) is more sensitive and specific compared to echocardiography for LVT detection, and may be appropriate for high-risk patients. Prolonged anticoagulation may be considered in unresolved protuberant or mobile LVT, and in patients with resolved LVT but persistent depressed left ventricular ejection fraction and/or myocardial akinesia or dyskinesia.

EXPERT OPINION

CMR will likely be increasingly used for LVT surveillance to guide anticoagulation duration. Further research is needed to determine which patients with persistent LVT on CMR benefit from prolonged anticoagulation.

Dilemmas in hematology: consults in patients with arterial thrombosis

Arterial thrombotic events, particularly ischemic stroke and myocardial infarction, are common, and mostly occur due to atherosclerotic disease or arrhythmias. The diagnosis and management of the majority of such events occurs without the involvement of a hematologist, following established guidelines or pathways. In this review, we discuss 3 scenarios in which optimal management is less certain. These scenarios concern patients with a left ventricular thrombus, in whom the duration and choice of anticoagulant has been debated, patients with ischemic stroke and a patent foramen ovale, in whom the role of patent foramen ovale closure requires careful consideration, and the role of thrombophilia testing in young patients after a stroke or myocardial infarction, which remains an area of contention. We consider the available evidence and published guidelines in order to provide a practical, evidence-based approach to these 3 clinical scenarios.

Direct oral anticoagulants compared with vitamin K antagonists for left ventricular thrombus: a systematic review and meta-analysis

Background:

Direct oral anticoagulants (DOACs) are the guideline-recommended therapy for some hypercoagulable diseases but are used off-label for left ventricular thrombus (LVT) owing to a paucity of evidence. We performed a meta-analysis to assess the safety and efficacy of DOACs compared with vitamin K antagonists (VKAs) for LVT treatment.

Methods:

We comprehensively searched PubMed, EMBASE, Cochrane Library, and Web of Science databases for studies that compared DOACs with VKAs for LVT treatment. Outcome indicators included stroke or systemic embolism (SSE), thrombus resolution, bleeding, and death. The Newcastle–Ottawa scale was used to evaluate the quality of included studies. Data were analyzed using Review Manager 5.3, and the meta-analysis is registered at PROSPERO (CRD 42020211376).

Results:

We included 12 observational studies (n = 2262 patients). SSE was similar for DOACs and VKAs groups (odds ratio [OR] = 1.01, 95% confidence interval [CI] 0.66–1.54, P = 0.95). For thrombus resolution, DOACs were not significantly different to VKAs (OR = 1.15, 95% CI 0.54–2.45, P = 0.71). DOACs and VKAs had a similar bleeding risk (OR = 0.78, 95% CI 0.45–1.35, P = 0.37). DOACs and VKAs groups had a comparable mortality (OR = 0.91, 95% CI 0.50–1.65, P = 0.76). Subgroup analysis showed that post-AMI (acute myocardial infarction) patients using DOACs had a lower risk of SSE (OR = 0.24, 95% CI 0.07–0.87, P = 0.03) and bleeding (OR = 0.38, 95% CI 0.18–0.81, P = 0.01).

Conclusion:

DOACs and VKAs showed no difference in the safety and efficacy of patients with LVT. DOACs might be superior to VKAs for LVT treatment in post-AMI patients.

Left Ventricular Thrombus Formation in a Young Female With a Severely Reduced Left Ventricular Ejection Fraction and a Recent Non-ST Segment Elevation-Acute Coronary Syndrome

A 30-year-old female with a past medical history of heart failure with reduced ejection fraction (HFrEF of 20%), non-ST segment elevation-acute coronary syndrome (NSTE-ACS), and polysubstance abuse (heavy alcohol and methamphetamine use) was admitted for a heart failure exacerbation. Electrocardiogram and troponin levels were negative. Pro brain natriuretic peptide was elevated at 4,152 pg/mL. The patient was restarted on guideline-directed HFrEF therapy and continued to improve. Two days after presentation, the patient was transferred to the intensive care unit for severe alcohol withdrawal, requiring intravenous phenobarbital and dexmedetomidine. After her withdrawal symptoms resolved, she complained of right-sided weakness and stroke-like symptoms. Brain magnetic resonance imaging (MRI) and computed tomography (CT) were both negative. Echocardiography revealed an ejection fraction of 20% and a severely dilated left ventricle with a 2.1 x 1.2 cm apical density, suggestive of a thrombus, and the patient was started on apixaban. Echocardiography two months prior to this admission revealed an ejection fraction of 20%, but there was no evidence of a thrombus. Our patient had three major risk factors for left ventricular thrombus (LVT) formation: severely reduced left ventricular ejection fraction (LVEF), dilated cardiomyopathy (DCM), and a recent NSTE-ACS two months prior. This case highlights the importance of anticoagulation in patients at high risk for LVT formation and emphasizes the DCM may be seen in younger patients with heavy alcohol and amphetamine use.

One-year clinical outcome of patients with left ventricular thrombus after acute myocardial infarction discharged on triple or dual antithrombotic therapy

In patients with left ventricular thrombus (LVT) after acute myocardial infarction (MI), both anticoagulant and antiplatelet therapies are needed. It is unknown whether dual antithrombotic therapy (DAT) is able to reduce the incidence of bleeding complications without significantly increasing the number of thromboembolic events, compared to triple antithrombotic therapy (TAT). We retrospectively evaluated all post-MI patients with LVT discharged on TAT or DAT from our tertiary hospital in the last decade. The primary outcome was the occurrence of all-cause mortality, thromboembolic events, hospitalizations for re-MI or heart failure and any bleeding at 1 year. A propensity-score matching was performed in order to compare the primary outcome between TAT and DAT. Out of 2564 acute MI patients, 83 (3.2%) had an LVT at echocardiography: 51 (61.4%) discharged on TAT and 32 (38.6%) on DAT. At clinical follow-up, completed in 93% of cases, the incidence of the primary outcome was 18.2% (25.5% in TAT and 6.7% in DAT group; p = 0.04). More than 2/3 of the events included in the primary outcome were related to bleeding complications and occurred during the first month from hospital discharge. In the matched cohort of 42 patients with follow-up data available, the primary outcome occurred in 9 (42.9%) patients in the TAT and 2 (9.5%) in the DAT group (p = 0.03). In post-MI patients with LVT, DAT seems more effective than TAT in reducing clinical outcome, especially early bleeding complications. A randomized study is warranted to confirm this hypothesis.

Video assisted, transaortic removal of left ventricular thrombus during concurrent cardiac surgery: a case report

INTRODUCTION

Left ventricular (LV) thrombus is a complication of acute myocardial infarction and is associated with systemic thromboembolism. We describe a trans-aortic endoscopic approach to the removal of an LV thrombus in a patient undergoing concurrent coronary artery bypass grafting and aortic valve replacement.

CASE PRESENTATION

A 47 year old male presented following an embolic middle cerebral artery stroke and underwent transthoracic echocardiography demonstrating a mobile LV thrombus. Additional investigation revealed a moderately stenosed bicispid aortic valve, two vessel coronary artery disease and ischemic cardiomyopathy. The patient underwent early surgery to reduce the risk of further embolic episodes. A trans-aortic approach was utilized with videoscopy and single shafted instrumentation to aide in removal of the thrombus. The patient then underwent aortic valve replacement and coronary artery bypass grafting.

CONCLUSION

We report an alternative technique for the removal of a left ventricular thrombus in a patient undergoing concurrent coronary and aortic valve surgery. The transaortic video-assisted approach provided excellent visualisation of the apex and near complete removal of the thrombus without damaging the surrounding trabeculae. The main benefit of this technique is sparing of LV tissue, thereby preserving left ventricular function.

EACVI recommendations on cardiovascular imaging for the detection of embolic sources: endorsed by the Canadian Society of Echocardiography

Cardioaortic embolism to the brain accounts for approximately 15-30% of ischaemic strokes and is often referred to as 'cardioembolic stroke'. One-quarter of patients have more than one cardiac source of embolism and 15% have significant cerebrovascular atherosclerosis. After a careful work-up, up to 30% of ischaemic strokes remain 'cryptogenic', recently redefined as 'embolic strokes of undetermined source'. The diagnosis of cardioembolic stroke remains difficult because a potential cardiac source of embolism does not establish the stroke mechanism. The role of cardiac imaging-transthoracic echocardiography (TTE), transoesophageal echocardiography (TOE), cardiac computed tomography (CT), and magnetic resonance imaging (MRI)-in the diagnosis of potential cardiac sources of embolism, and for therapeutic guidance, is reviewed in these recommendations. Contrast TTE/TOE is highly accurate for detecting left atrial appendage thrombosis in patients with atrial fibrillation, valvular and prosthesis vegetations and thrombosis, aortic arch atheroma, patent foramen ovale, atrial septal defect, and intracardiac tumours. Both CT and MRI are highly accurate for detecting cavity thrombosis, intracardiac tumours, and valvular prosthesis thrombosis. Thus, CT and cardiac magnetic resonance should be considered in addition to TTE and TOE in the detection of a cardiac source of embolism. We propose a diagnostic algorithm where vascular imaging and contrast TTE/TOE are considered the first-line tool in the search for a cardiac source of embolism. CT and MRI are considered as alternative and complementary tools, and their indications are described on a case-by-case approach.

The role of echocardiography in the embolic stroke of undetermined source

: Echocardiography plays an important role both in the diagnosis and the treatment/prevention of embolic stroke of undetermined source and should be performed as soon as possible for preventing ischemic stroke recurrencies, which occur more frequently during the first week after the first ischemic event. Early identification of the cause of a transient ischemic attack or stroke is indeed a primary goal for the neurologist in the Stroke Unit and requires specific diagnostic strategies. Echocardiography, together with other diagnostic tools such as carotid and transcranial ultrasounds, provides this information promptly. In particular, echocardiography might be able to detect the main sources of the embolic stroke, such as atrial fibrillation, ventricular akinesia, aortic atheroma plaques and/or cardiac shunts. The present review discusses the importance and the practical role of echocardiography as a crucial diagnostic tool for detecting the main source of emboli in the setting of the acute stroke.

Neurological complications of coronary heart disease and their management

While risk factors for the development of neurovascular and coronary heart disease (CHD) are similar, it is important to consider neurologic complications of CHD separately, as many of these complications are a direct result of the underlying condition or procedures performed to treat atherosclerotic coronary disease. Stroke after myocardial infarction (MI) and acute coronary syndromes (ACSs) is not infrequent, occurring in 0.7%-2.5% of patients within 6 months of the coronary event. The etiology of these events can be frequently traced to the development of left ventricular thrombus (LVT) formation after large MI episodes. Often, however, these events are directly related to catheter-based procedures or anticoagulation strategies utilized to treat the ACS. Ischemic strokes outnumber hemorrhagic strokes in this population. While there is a modest evidence base for use of anticoagulation to treat LVT, catheterization-related ischemic stroke and anticoagulation-related hemorrhagic stroke are typically managed via standard approaches.

Associations between the size and location of myocardial infarction and cerebral infarction

BACKGROUND

Myocardial infarction (MI) is a known cause of cerebral infarction. We assessed whether the size and location of MI is associated with the risk of cerebral infarction.

METHODS AND RESULTS

We performed a cross-sectional study of adults who underwent both brain MRI and delayed-enhancement cardiac MRI (DE-CMR) within 365 days of each other at Weill Cornell Medicine between 2014 and 2017 and had evidence of MI on DE-CMR. We used multiple logistic regression to evaluate associations between MI size and any cerebral infarction, apical MI location and any cerebral infarction, and MI size/location and cortical versus subcortical cerebral infarction. Models were adjusted for demographics, and the total number of vascular risk factors. Among 234 patients who underwent both DE-CMR and brain MRI within 365 days, 76 had evidence for MI on DE-CMR. Among these 76 patients, 51 (67.1%) had evidence of cerebral infarction. The size of MI (global MI burden) was not associated with any cerebral infarction (OR per 5% increase in MI size, 1.12; 95% CI, 0.85-1.47), but was associated with cortical cerebral infarction (OR per 5% increase in MI size, 1.30; 95% CI, 1.00.-1.68). Similarly, apical MI location was not associated with any cerebral infarction (OR 2.63, 95% CI, 0.78-8.87), but was associated with cortical cerebral infarction (OR, 3.67; 95% CI, 1.19-11.33).

CONCLUSION

Among patients with MI on cardiac MRI, both size and apical location of MI were associated with cortical cerebral infarction. Our results may help stratify cardioembolic risk and inform antithrombotic treatment algorithms among patients with MI.

Peripheral embolization following thrombolytic therapy for acute ischemic stroke—a case report

Background

Intravenous recombinant tissue plasminogen activator is the only golden approved medical therapy for acute ischemic stroke, guidelines for its injection relay on reducing or preventing associated hemorrhage as a side effect, yet hemorrhage is not the only possible complication, further embolization following injection is also a possibility; in this case report, peripheral embolization following intravenous recombinant tissue plasminogen activator with two possible explanations one related to the treatment and another related to the patient liability is represented.

Case presentation

A 78-year-old male presenting with acute onset of stroke, received intravenous recombinant tissue plasminogen activator, 16 h later he developed acute limb ischemia.

Conclusion

Peripheral embolization may happen within hours from intravenous recombinant tissue plasminogen activator administration.

Successful surgical transmitral removal of left ventricular thrombus after acute anterior myocardial infarction without left ventriculotomy

Left ventricular thrombus (LVT) is known as a life-threatening complication of acute myocardial infarction, in terms of sequential systemic embolization. When an LVT is found to be sufficiently large or mobile, not only anticoagulation therapy but also surgical thrombectomy should be administered immediately to prevent embolic events. Generally, since infarcted myocardium is comparatively fragile, ventriculotomy may result in anastomotic failure or further deterioration of LV function. We report herein a case of transmitral removal of LVT by which we successfully avoided ventriculotomy. A 50-year-old Japanese man was hospitalized due to ST-segment elevation myocardial infarction and emergency coronary angiography revealed total occlusion at the proximal left anterior descending artery. On hospital day 9, transthoracic echocardiography detected a massive LVT at the apex, protruding into the left ventricle. Considering the risk of embolization, urgent thrombectomy via a transmitral approach was performed. The LVT was easily removed through the mitral valve under endoscopic support, without any embolic events or postoperative complications. <Learning objective: Left ventricular thrombus following acute myocardial infarction may result in fatal embolization. Although surgical removal should be considered to prevent embolic events, some previous reports state that surgical approaches such as left ventriculotomy can lead to further cardiac dysfunction and ruptured sutures. Thus, transmitral approach may be useful for avoiding embolic events without left ventriculotomy and sequential complications.>.

Association Between C-Reactive Protein to Albumin Ratio and Left Ventricular Thrombus Formation Following Acute Anterior Myocardial Infarction

Left ventricular thrombus (LVT) is associated with inflammatory response in survivors with anterior ST-elevation myocardial infarction (STEMI). The C-reactive protein to albumin ratio (CAR) has been proposed as a marker of inflammation. However, there is a lack of data with respect to the role of CAR in LVT development. We investigated the relationship between CAR and LVT development in patients with anterior STEMI treated percutaneously; 955 consecutive patients were enrolled and LVT was observed in 126 (13.2%) patients. Clinical, demographic, and laboratory parameters were recorded. The CAR was significantly higher in patients with LVT (12.6 [8.6-16.1] vs 18.1 [11.5-23], P < .001). Other independent predictors for LVT development were lower ejection fraction, the presence of left ventricular apical aneurysm, proximal left anterior descending lesion location, glycoprotein IIb/IIIa inhibitors treatment, >1 diseased arteries, higher total protein level, neutrophil count, and peak creatine kinase myocardial band activity. In conclusion, the CAR may be useful as a simple tool for predicting LVT development among survivors of anterior STEMI.

Usefulness of whole blood viscosity estimated by de Simeone's formula to predict left ventricular thrombus formation within one year following acute anterior myocardial infarction

BACKGROUND

Despite improvements in treatment of ST-segment myocardial infarction (STEMI), thrombus formation in the left ventricle is still a concerning complication that may lead to systemic thromboembolism and stroke.

OBJECTIVES

To evaluate the predictive value of estimated whole blood viscosity (WBV) for left ventricular thrombus development in patients surviving an acute anterior myocardial infarction (AAMI).MATERIALS \& METHODS:Seven hundred eighty AAMI patients who were treated percutaneously were enrolled consecutively. Serial echocardiographic examinations were performed within 24h of admission, before hospital discharge, and at 1, 3, 6 and 12 months following hospital discharge. WBV was calculated according to de Simones formula.

RESULTS

One hundred patients (12.8%) developed thrombus formation within one year following AAMI. Patients with left ventricular thrombus (LVT) had significantly higher WBV values. Supramedian values of WBV at both low (0.5 sec-1) and high (208 sec-1) shear rates were found to be an independent predictor of LVT development.

CONCLUSION

As an easily accessible parameter, WBV might be a useful predictor of LVT formation within one year following acute anterior myocardial infarction.

The prognostic effect of left ventricular thrombus formation after acute myocardial infarction in the contemporary era of primary percutaneous coronary intervention: A meta-analysis

BACKGROUNDS

The prognosis and management of left ventricular thrombus (LVT) following acute myocardial infarction (AMI) have not been well evaluated since the advent of primary percutaneous coronary intervention (PCI). We therefore conducted a meta-analysis to assess the prognostic effect of LVT after AMI in primary PCI era and investigate the impact of triple therapy on outcomes.

METHODS

We searched MEDLINE, EMBASE and the Cochrane Library for studies conducted in primary PCI era up to 29 March 2019, compering the incidence of embolic events and mortality after AMI between LVT patients and Non-LVT patients. Random-effect models were used. Subgroup analysis was done by comparing triple therapy treated LVT group with Non-LVT group.

RESULT

A total of 12 studies were included. LVT was associated with increased risk of embolic events and long-term mortality (RR 3.97, 95%CI 2.68-5.89, P < 0.0001; RR 2.34, 95%CI 1.38-3.96, P = 0.002). Subgroup analysis was also done by comparing triple therapy treated LVT group with Non-LVT group. Despite a downward tendency was observed, the embolic risk of triple therapy subgroup was higher than non-LVT group (RR 2.79, 95%CI 1.32-5.91, P = 0.007). Triple therapy subgroup had a similar mortality rate compared with non-LVT group (RR 0.93, 95%CI 0.34-2.52, P = 0.88).

CONCLUSION

In primary PCI era, LVT formation after AMI indicated a fourfold increased embolic risk and twofold long-term mortality rate. Triple therapy may be a safe way to improve the outcomes, but still need to be confirmed by future trials.

Role of Imaging for Suspected Cardiac Thrombus

PURPOSE OF REVIEW

Cardiac thrombus formation is a frequent complication of a variety of prevalent diseases. Embolism of cardiac thrombus has the potential to result in significant morbidity and mortality from cerebrovascular and peripheral vascular events.

RECENT FINDINGS

Echocardiography is the most commonly used imaging modality for diagnosing intracardiac thrombus. However, technological advances in computed tomography and magnetic resonance imaging have allowed newer noninvasive modalities to evolve into robust tools for the clinical evaluation of patients suspected of disease. Complimentary use of these imaging techniques is crucial in the diagnosis of cardiac thrombus and initiation of anticoagulation therapy.

Recent Myocardial Infarction is Associated With Increased Risk in Older Adults With Acute Ischemic Stroke Receiving Thrombolytic Therapy

Background

Intravenous recombinant tissue‐type plasminogen activator (rtPA) remains the only medical therapy to improve outcomes for acute ischemic stroke (AIS), but the safety of rtPA in AIS patients with a history of recent myocardial infarction (MI) remains controversial.

Methods and Results

We sought to determine whether the presence of recent MI would alter the risk of mortality and rtPA‐related complications. Multivariate logistic regression models were used to compare in‐hospital outcomes between rtPA‐treated AIS patients with recent MI within 3 months and those with no history of MI from the Get With The Guidelines‐Stroke hospitals between February 2009 and December 2015. Among 40 396 AIS patients aged ≥65 years treated with rtPA, 241 (0.6%) had recent MI, of which 19.5% were ST‐segment–elevation myocardial infarction. Patients with recent MI had more severe stroke than those without (median National Institutes of Health Stroke Scale [interquartile range]: 13.0 [7.0–20.0] versus 11.0 [6.0–18.0]). Recent MI was associated with an increased risk of mortality compared with no history of MI (17.4% versus 9.0%; adjusted odds ratio 1.60 [95% CI, 1.10–2.33]; P=0.014), but no statistically significant differences in rtPA‐related complications (13.5% versus 9.4%; adjusted odds ratio 1.28 [0.88–1.86]; P=0.19). Recent ST‐segment–elevation myocardial infarction was associated with higher risk of death and rtPA‐related complications, but non–ST‐segment–elevation myocardial infarction was not.

Conclusions

Among older AIS patients treated with rtPA, recent MI was associated with an increased risk of in‐hospital mortality. Further investigations are necessary to determine whether the benefit of rtPA outweighs its risk among AIS patients with recent MI.

Usefulness of apical area index to predict left ventricular thrombus in patients with systolic dysfunction: a novel index from cardiac magnetic resonance

BACKGROUND

LV systolic dysfunction presents an elevated risk of thromboembolism. Previous studies demonstrated low left ventricular ejection fraction (LVEF), ischemic cardiomyopathy and increased myocardial scarring as independent risk factors for LV thrombus formation. Structural changes that alter the size and shape of LV apex may have a significant role in predicting LV thrombus, but there is no definite evidence exists in this entity.

METHODS

A case-control cardiac magnetic resonance (CMR) study of 150 patients with LV systolic dysfunction (LVEF < 40%; 30 patients with LV thrombus and 120 patients without thrombus) was performed. Factors associated with thrombus including sphericity index and 'new' apical area index (ratio of apical area to entire LV area from a cine four-chamber view) were evaluated.

RESULTS

Average age was 63.48 ± 12.82 years and mean LVEF was 29.22 ± 8.53%. Patients with LV thrombus had significantly higher apical area index than those without thrombus (46.5 ± 3.27 vs. 42.71 ± 3.02, p <  0.001) while sphericity index in both groups was not different (1.63 ± 0.27 vs. 1.67 ± 0.19, p = 0.57). Univariate analysis revealed that male gender, prior myocardial infarction, presence of apical aneurysm, ischemic-typed scar, apical scar and apical area index were associated with thrombus. Further, multivariate analysis showed only apical area index and apical scar as independent predictors for thrombus formation.

CONCLUSION

Apical area index from CMR is a new index to predict LV thrombus in patients with LV systolic dysfunction and may have a future role in early anticoagulant therapy.

Relationship of left ventricular thrombus formation and adverse outcomes in acute anterior myocardial infarction in patients treated with primary percutaneous coronary intervention

BACKGROUND

The incidence of left ventricular thrombus (LVT) is 4% to 15% in patients with anterior acute ST-segment elevation myocardial infarction (ant-AMI) in the era of primary percutaneous coronary intervention (PPCI). And patients with LVT have higher in-hospital mortality.

HYPOTHESIS

There is a relationship between LVT formation and 1-year major adverse cardio-cerebrovascular events (MACCE) in patients with ant-AMI treated by PPCI.

METHODS

Our study population included 1488 consecutive patients with ant-AMI. The primary endpoint was the incidence of MACCE within 1 year after AMI. The secondary endpoint was the thrombosis disappearance.

RESULTS

A total of 106 (7.1%) patients were diagnosed with LVT and 1382 (92.9%) patients without LVT. Patients with LVT had a higher incidence of MACCE than in patients without LVT (21.7%vs10.3%; P < 0.001). Univariate analysis showed LVT was associated with an increase in MACCE risk (odds ratio [OR] = 2.40; 95% confidence interval [CI] [1.37-4.21]; P < 0.001). When examining MACCE components individually, LVT was only associated with the incidence of congestive heart failure (OR = 2.41; 95% CI [1.29-4.58]; P = 0.001). After adjustment for principal confounders, LVT remained an independent risk factor for MACCE (HR = 2.28; 95% CI [1.12-6.38]; P = 0.020). Other independent predictors include 24-hour LVEF, creatine kinase peak value, and age. Further analysis found patients with LVT in international normalized ratio (INR) ≥ 2 group had lower MACCE risk and higher thrombus disappearance than in INR < 2 group (13.5%vs29.6%; P = 0.044; 90.4%vs74.1%; P = 0.029).

CONCLUSION

For patients with ant-AMI treated by PPCI, LVT is an independent predictor of 1-year MACCE events. Treatment with vitamin K antagonist in the therapeutic range (INR ≥ 2) has the potential to reduce MACCE risk and promote disappearance of thrombus.

Left ventricular thrombus formation in myocardial infarction is associated with altered left ventricular blood flow energetics

Aims

The main aim of this study was to characterize changes in the left ventricular (LV) blood flow kinetic energy (KE) using four-dimensional (4D) flow cardiovascular magnetic resonance imaging (CMR) in patients with myocardial infarction (MI) with/without LV thrombus (LVT).

Methods and results

This is a prospective cohort study of 108 subjects [controls = 40, MI patients without LVT (LVT- = 36), and MI patients with LVT (LVT+ = 32)]. All underwent CMR including whole-heart 4D flow. LV blood flow KE wall calculated using the formula: KE=12 ρblood . Vvoxel . v2, where ρ = density, V = volume, v = velocity, and was indexed to LV end-diastolic volume. Patient with MI had significantly lower LV KE components than controls (P < 0.05). LVT+ and LVT- patients had comparable infarct size and apical regional wall motion score (P > 0.05). The relative drop in A-wave KE from mid-ventricle to apex and the proportion of in-plane KE were higher in patients with LVT+ compared with LVT- (87 ± 9% vs. 78 ± 14%, P = 0.02; 40 ± 5% vs. 36 ± 7%, P = 0.04, respectively). The time difference of peak E-wave KE demonstrated a significant rise between the two groups (LVT-: 38 ± 38 ms vs. LVT+: 62 ± 56 ms, P = 0.04). In logistic-regression, the relative drop in A-wave KE (beta = 11.5, P = 0.002) demonstrated the strongest association with LVT.

Conclusion

Patients with MI have reduced global LV flow KE. Additionally, MI patients with LVT have significantly reduced and delayed wash-in of the LV. The relative drop of distal intra-ventricular A-wave KE, which represents the distal late-diastolic wash-in of the LV, is most strongly associated with the presence of LVT.

Left ventricular thrombosis in acute anterior myocardial infarction: Evaluation of hospital mortality, thromboembolism, and bleeding

BACKGROUND

Left ventricular thrombosis (LVT) is a well-known complication of acute myocardial infarction, most commonly seen in anterior wall ST-segment elevation myocardial infarction (STEMI). It is associated with systemic thromboembolism.

HYPOTHESIS

Our aim was to evaluate the impact of LVT on in-hospital mortality, thromboembolism, and bleeding in patients with anterior STEMI.

METHODS

Data was collected from the Nationwide Inpatient Sample where patients with a primary diagnosis of "Anterior STEMI" [ICD9-CM code 410.1] were included. Comparisons were made between patients with LVT [ICD9-CM code 429.79] vs those without using propensity score matching (PSM).

RESULTS

From 2002 to 2014, there were 157 891 cases of anterior STEMI. Among these, 649 (0.4%) had LVT. Post-PSM, there was no difference in in-hospital mortality between the groups with LVT and without (7.3% vs 8.6%). Thromboembolic event rate was higher with LVT compared to those without LVT (7.3% vs 2.1%). There was no difference in bleeding events between patients with LVT and those without (2.9% vs 3.2%). The baseline average length of stay in the group with LVT was longer than the group without LVT (7.9 ± 6.7 days vs 5.1 ± 6.0 days). The average hospitalization-related costs were also significantly higher among patients with LVT compared to those without (95 598 USD vs 66 641 USD per stay) at baseline.

CONCLUSION

Among patients hospitalized with anterior STEMI, presence of LVT is associated with increased thromboembolic events, average length of hospital stay and average cost of hospitalization. However, it is not associated with increased in-hospital mortality or bleeding events.

Safety and Efficacy of Triple Therapeutic Targets with Rivaroxaban after Acute Myocardial Infarction Complicated by Left Ventricular Thrombi in a Case of Nonvalvular Atrial Fibrillation

We present the complex case of a high-risk patient with nonvalvular atrial fibrillation, who experienced a non-ST elevation myocardial infarction complicated by left ventricular (LV) thrombi and underwent percutaneous coronary intervention with drug-eluting stent implantation. The patient was initially treated with short-term triple therapy including aspirin, clopidogrel, and rivaroxaban 15 mg/die. Following aspirin dropping one month after discharge, the patient continued on dual therapy with clopidogrel and rivaroxaban, and a clinical and imaging follow-up at 6 and 12 months confirmed the LV thrombi resolution, with no thromboembolic episodes and a good safety profile.

Carotid Artery Stenting

Carotid artery stenosis is relatively common and is a significant cause of ischemic stroke, but carotid revascularization can reduce the risk of ischemic stroke in patients with significant symptomatic stenosis. Carotid endarterectomy has been and remains the gold standard treatment to reduce the risk of carotid artery stenosis. Carotid artery stenting (CAS) (or carotid artery stent implantation) is another method of carotid revascularization, which has developed rapidly over the last 30 years. To date, the frequency of use of CAS is increasing, and clinical outcomes are improving with technical advancements. However, the value of CAS remains unclear in patients with significant carotid artery stenosis. This review article discusses the basic concepts and procedural techniques involved in CAS.

Complete Resolution of the Left Ventricular Pedunculated Thrombus with Tirofiban Infusion in a Patient with Severe Left Ventricular Dysfunction

A 28-year-old man was admitted with symptoms of heart failure. Echocardiography revealed severe left ventricular dysfunction, apical aneurysm, and a 40 × 11 mm sized mobile thrombus attached to apical septum with a narrow stalk. The patient had anterior myocardial infarction two years ago. Heparin infusion was started at 1000 IU/hour for 48 hours. There was no detected change on the size of the thrombus. Surgery recommended to the patient was refused by him because of the procedural risks. Tirofiban infusion was started. Repeat echocardiography showed significant reduction in thrombus size after 24 hours, and complete resolution of the thrombus after 48 hours. To our knowledge, this is the first case with left ventricular mobile thrombus treated successfully with tirofiban infusion.

Impaired left ventricular diastolic function is related to the formation of left ventricular apical thrombus in patients with acute anterior myocardial infarction

Left ventricular (LV) apical thrombus is a clinically important complication which can cause systemic embolization in patients with anterior acute myocardial infarction (AMI). Systolic dysfunction has been a risk factor for developing LV apical thrombus in AMI patients. However, the role of diastolic dysfunction in the development of LV apical thrombus in these patients is still unknown. We performed this study to evaluate whether diastolic dysfunction can influence the development of LV apical thrombus in anterior AMI patients. We retrospectively analyzed all consecutive anterior AMI patients with available echocardiographic images within 1 month from January 2005 to April 2016. After gathering clinical characteristics from their medical records, systolic and diastolic functions were analyzed from digitally stored echocardiographic images. We included a total of 1045 patients (748 males, mean age 64 ± 12 years) with anterior AMI, and 494 (47%) were diagnosed as STEMI. The incidence of LV apical thrombus was 3.3% (34/1045). The LV apical thrombus group had larger LV diastolic dimension, larger LV diastolic and systolic volumes, and lower LVEF than the no LV thrombus group. The LV apical thrombus group showed higher mitral E velocity over mitral annular E' velocity ratio, an indicator of LV end-diastolic pressure (P < 0.001). In the LV apical thrombus group, the incidence of grade 2 diastolic dysfunction (32 vs 12%, P = 0.001) and grade 3 diastolic dysfunction (26 vs 2%, P < 0.001) were significantly higher than in the no LV apical thrombus group. The presence of more than grade 2 diastolic dysfunction, LVEF and presence of LV apical aneurysm were statistically significant factors associated with LV apical thrombus after the multivariate analysis. In conclusion, along with LV systolic dysfunction and LV apical aneurysm, LV diastolic dysfunction was also related with the presence of LV apical thrombus in patients with anterior AMI.

Prevention of Left Ventricular Thrombus Formation and Systemic Embolism After Anterior Myocardial Infarction: A Systematic Literature Review

BACKGROUND

Anterior myocardial infarction (MI) with apical dysfunction is associated with an increased risk of left ventricular thrombus (LVT) formation and systemic embolism (SE). However, the role for prophylactic anticoagulation in current practice is a matter of debate.

METHODS

We conducted a systematic review of peer-reviewed original articles in either English or French on the benefit of combining anticoagulation with standard therapy for the prevention of LVT/SE after MI by searching PubMed, Ovid/MedLine/Embase, the Cochrane Library, and Google Scholar.

RESULTS

Of 7382 identified records, 14 were retained for analysis. Nine articles addressed anticoagulation for patients not treated with percutaneous coronary intervention (PCI). Another 5 included at least some patients treated with PCI. Only 1 study specifically addressed exclusively a primary PCI population. Some studies showed a benefit for combining anticoagulation with standard therapy in patients not treated with PCI, but results were inconsistent. No evidence of benefit was reported when PCI patients were included and 1 study reported a signal for net harm. There was important interstudy heterogeneity and methodological limitations. Studies were likely individually underpowered.

CONCLUSIONS

The available studies of LVT/SE prevention after MI lacked statistical power and are heterogeneous in terms of treatments, revascularization methods, background medical therapy, and study design. We conclude that there is presently no compelling evidence for or against combining anticoagulation with standard therapy for post-MI patients with apical dysfunction after primary PCI, and inconsistent evidence supporting prophylaxis after thrombolysis. An appropriately powered randomized trial is required to answer this clinically relevant question.

Challenges in management of left ventricular thrombus

Left ventricular thrombus (LVT) complicates both ischemic and non-ischemic cardiomyopathies and is a potential cause of thromboembolic complications such as stroke. Management of LVT in the 21st century is primarily based on studies before the widespread use of potent pharmacological and interventional therapies such as primary percutaneous coronary intervention, especially in the setting of acute myocardial infarction. Though advances in diagnostic technology have improved detection of LVT, clinicians face several uncertainties in the management of LVT in daily practice. The aim of this paper is to examine several controversies in the diagnosis and management of LVT. Prospective studies are needed to advance therapy of LVT.

Large In-transient Left Ventricular Thrombus due to Anabolic Steroid-induced Cardiomyopathy

The presence of small or moderate size thrombosis is not uncommon in left ventricle (LV) as results of basic co-moribund disease, but huge LV thrombosis that protrudes to aortic valve in the LV outflow tract (LVOT) tract is an exceptionally rare phenomenon. We report a 34-year-old bodybuilder athlete with cardiomyopathy and massive LV thrombosis. The thrombosis extended to LVOT and protruded through the aortic valve in systole and posed a high risk of systemic emboli. The patient underwent open heart surgery, and the clot was removed. The operation was complicated by low cardiac output syndrome that managed by intra-aortic balloon pump and high dose of inotropic drugs and hemodialysis. The patient died on the 15^th day after surgery with multiorgan failures.

Clinical predictors and outcomes of patients with left ventricular thrombus following ST-segment elevation myocardial infarction

We aimed to characterize the independent predictors of LVT following STEMI and the association with outcomes. The clinical predictors of left ventricular thrombus (LVT) formation after ST-segment elevation myocardial infarction (STEMI) are not well-defined in the contemporary era. We performed a retrospective analysis of STEMI patients at Duke from 2000 to 2011 who had a transthoracic echocardiogram within 90 days post-STEMI and compared patients with and without LVT (LVT+ vs. LVT-). Univariate Cox proportional hazards regression models of baseline characteristics were examined and significant variables were used in a multivariable model to assess adjusted relationships with LVT. A multivariable Cox PH survival model with covariate adjustments was used for assessment of LVT and long-term mortality. Of all eligible patients, 1734 patients met inclusion criteria and 4.3 % (N = 74) had a LVT. LVT+ patients tended to have a history of heart failure (HF) and higher initial troponin compared to LVT- patients. After adjustment, higher heart rate, non-white race, HF severity, and presence of left anterior descending artery (LAD) disease were independent predictors of LVT. There was a trend toward an association between LVT and increased all-cause mortality (HR 1.36; 95 % CI 0.84-2.21, P = 0.22), however this was not statistically significant. LVT was seen in over 4 % of this contemporary post-STEMI population. Several baseline characteristics were independently associated with LVT: Heart rate, HF severity, LAD disease, and non-white race. Prospective studies are warranted to determine whether anticoagulation in patients at increased risk for LVT improves outcomes.

Guidelines for the Use of Echocardiography in the Evaluation of a Cardiac Source of Embolism

Embolism from the heart or the thoracic aorta often leads to clinically significant morbidity and mortality due to transient ischemic attack, stroke or occlusion of peripheral arteries. Transthoracic and transesophageal echocardiography are the key diagnostic modalities for evaluation, diagnosis, and management of stroke, systemic and pulmonary embolism. This document provides comprehensive American Society of Echocardiography guidelines on the use of echocardiography for evaluation of cardiac sources of embolism. It describes general mechanisms of stroke and systemic embolism; the specific role of cardiac and aortic sources in stroke, and systemic and pulmonary embolism; the role of echocardiography in evaluation, diagnosis, and management of cardiac and aortic sources of emboli including the incremental value of contrast and 3D echocardiography; and a brief description of alternative imaging techniques and their role in the evaluation of cardiac sources of emboli. Specific guidelines are provided for each category of embolic sources including the left atrium and left atrial appendage, left ventricle, heart valves, cardiac tumors, and thoracic aorta. In addition, there are recommendation regarding pulmonary embolism, and embolism related to cardiovascular surgery and percutaneous procedures. The guidelines also include a dedicated section on cardiac sources of embolism in pediatric populations.

Ischemic Stroke Risk After Acute Coronary Syndrome

BACKGROUND

Prior studies show an increased risk of ischemic stroke (IS) after myocardial infarction; however, there is limited evidence on long-term risk and whether it is directly related to cardiac injury. We hypothesized that the risk of IS after acute coronary syndrome is significantly higher if there is evidence of cardiac injury, such as ST-segment elevation myocardial infarction (STEMI) or non-STEMI, than when there is no evidence of cardiac injury, such as in unstable angina.

METHODS AND RESULTS

Administrative claims data were obtained from all emergency department encounters and hospitalizations at California's nonfederal acute care hospitals between 2008 and 2011. Patients with STEMI, non-STEMI, and unstable angina were identified using appropriate International Classification of Diseases, Ninth Revision, Clinical Modification codes. The primary outcome was IS during 2 years of follow-up. Unadjusted and adjusted Cox proportional hazards models were used to determine the association between acute coronary syndrome subtype and IS risk. We identified 73 059 patients with a diagnosis of STEMI (n=26 427), non-STEMI (n=39 833), or unstable angina (n=6819) during the study period. In the fully adjusted models that included potential confounders such as atrial fibrillation and congestive heart failure, the risk of IS was higher with STEMI (hazard ratio 4.17, 95% CI 3.00-5.83; P<0.001) and non-STEMI (hazard ratio 3.73, 95% CI 2.68-5.19, P<0.001) compared with unstable angina.

CONCLUSIONS

Non-STEMI and STEMI confer an equally increased risk of IS. Studies exploring IS mechanisms in cardiac patients are needed to improve and tailor stroke prevention strategies.

A coupled chemo-fluidic computational model for thrombogenesis in infarcted left ventricles

A coupled chemo-fluidic computational model for investigating flow-mediated thrombogenesis in infarcted left ventricles (LVs) is proposed. LV thrombus (LVT) formation after the acute myocardial infarction (AMI) may lead to thromboembolic events that are associated with high mortality and morbidity, and reliable stratification of LVT risk is the key to managing the treatment of AMI patients. There have been several studies emphasizing the importance of LV blood flow patterns on thrombus formation; however, given the complex interplay between ventricular flow dynamics and biochemistry of thrombogenesis, current understanding is mostly empirical. In the present model, blood flow in the LV is obtained by solving the incompressible Navier-Stokes equations, and this is coupled to the biochemical modeling of the coagulation cascade, platelet activation, and fibrinogen polymerization. The coupled model is used to examine the effect of ventricular flow patterns on thrombogenesis in modeled ventricles. It is expected that the method developed here will enable in-depth studies of thrombogenesis in patient-derived infarcted LV models.

Clinical Characteristics and Risk Factors of Left Ventricular Thrombus after Acute Myocardial Infarction: A Matched Case-control Study

Background:

Left ventricular thrombus (LVT) is reported to be a common complication in acute myocardial infarction (AMI) patients. And it has the potential to cause systemic embolism. This retrospective study was to present the current situation of LVT in clinical practice, as well as to evaluate the clinical characteristics and the risk factors of LVT after AMI.

Methods:

LVT cases (n = 96) were identified from 13,732 AMI (non-ST elevation myocardial infarction was excluded) patients in Fuwai Hospital's electronic medical records system from January 2003 to January 2013. The controls (n = 192) were gender- and age-matched AMI patients without LVT during this period. A conditional logistic regression (fitted by the Cox model) was performed to identify the independent risk factors.

Results:

The incidence of LVT after AMI was 0.7%. Univariate analysis indicated that the anterior myocardial infarction (especially extensive anterior myocardial infarction), lower left ventricular ejection fraction (LVEF), LVEF ≤40%, severe regional wall motion abnormalities (RWMA), pericardial effusion, and left ventricular aneurysm were all related to LVT after AMI. The independent risk factors obtained from the conditional logistic regression analysis were lower LVEF (odds ratio (OR) = 0.891, 95% confidence interval (CI): 0.828–0.960), extensive anterior myocardial infarction (OR = 6.403, 95% CI: 1.769–23.169), severe RWMA (OR = 7.348, 95% CI: 1.323–40.819), and left ventricular aneurysm (OR = 6.955, 95% CI: 1.673–28.921).

Conclusions:

This study indicated that lower LVEF, extensive anterior myocardial infarction, severe RWMA, and left ventricular aneurysm were independent risk factors of LVT after AMI. It also suggested that further efforts are needed for the LVT diagnosis after AMI in clinical practice.

Ischemic Left Ventricular Perforation Covered by a Thrombus in a Patient Presenting with Cerebral Ischemia: Importance of Time-Sensitive Performance and Adequate Interpretation of Bedside Transthoracic Echography

If myocardial infarction remains silent, only clinical signs of complications may unveil its presence. Life-threatening complications include myocardial rupture, thrombus formation, or arterial embolization. In the presented case, a 76-year-old patient was admitted with left-sided hemiparesis. In duplex sonography, a critical stenosis of the right internal carotid artery was identified and initially but retrospectively incorrectly judged as the potential cause for ischemia. During operative thromboendarterectomy, arterial embolism of the right leg occurred coincidentally, more likely pointing towards a cardioembolic origin. Percutaneous interventions remained unsuccessful and local fibrinolysis was applied. Delayed bedside echocardiography by an experienced cardiologist demonstrated a discontinuity of the normal myocardial texture of the left ventricular apex together with an echodense, partly floating structure merely attached by a thin bridge not completely sealing the myocardial defect, accompanied by pericardial effusion. The patient was immediately transferred to emergency cardiac surgery with extirpation of the thrombus, aortocoronary bypass graft placement, and aneurysmectomy. This didactic case reveals decisive structural shortcomings in patient's admission and triage processes and underlines, if performed timely and correctly, the value of transthoracic echocardiography as a noninvasive and cost-effective tool allowing immediate decision-making, which, in this case, led to the correct but almost fatally delayed diagnosis.